This invention relates to improvements in mimeograph devices and more particularly, to a mimeograph device of the type which holds a predetermined amount of ink in the ink holding chamber defined therein and has a stencil paper bearing information comprising letters, numerals and/or symbols cut thereon applied to the air-ink permeable assembly so as to print the information on an article.
There have been proposed and practically employed a great variety of mimeograph devices and one of the prior art mimeograph device is shown in FIG. 1 of the accompanying drawings. The prior art mimeograph device generally comprises a rectangular support frame 1 having a pair of side legs 2,2 and a pair of end legs (not shown) which integrally depend from the undersurface of the frame in positions adjacent to and inwardly spaced from the associated side and end edges thereof, respectively and a center through hole 3 for the purpose to be described hereinafter. A perforated ink holding plate 4 having a U-shaped cross-section as seen in end elevation is held in position on the undersurface of the support frame 1 with the opposite upright side arms 5,5 and opposite upright end arms (not shown) of the plate suitably attached to the undersurface of the support frame 1 and the intermediate portion 6 convexed downwardly to thereby define an ink holding chamber 7 between the support frame and perforated plate. An air and liquid permeable resilient member 8 formed of sponge is applied to the outer surface or undersurface of the perforated plate 4 and a screen 9 is applied to the outer surface or undersurface of the sponge member and the screen may be formed of a piece of cloth, for example. A mimeograph original such as a stencil paper 10 having information comprising letters, numerals and/or symbols cut thereon is applied to the outer surface or undersurface of the screen 9. A hollow knob 11 is received and held in position in the center through hole 3 in the support frame 1 and the knob has spaced upper and lower brackets 12, 13 adjacent to the lower end of the knob which brackets are snugly fitted on the periphery defining the center through hole 3. The low bracket 13 is provided with a hole (not shown) and the support frame 1 also has a hole (not shown) which is adapted to communicate with the hole in the lower bracket when ink is to be charged into the ink holding chamber 7 as the knob 11 is turned so as to align the hole in the lower bracket 13 with the hole in the support frame 1. With the above-mentioned arrangement, when it is desired to print the information of the stencil paper 10 on a sheet of paper (not shown), for example, the user grips the knob 11 and applies the stencil paper 10 against the paper sheet with a slight pressure whereby the ink in the ink holding chamber 4 is permitted to permeate through the perforated plate 4, sponge 8, screen 9 and the cut information on the stencil paper 10 under pressure and the information is printed on the paper sheet.
However, in the prior art mimeograph device referred to hereinabove, since the through hole 3 in the support frame 1 in which the knob 11 is received also serves as the ink charging port, if the effective area of the perforated plate 4 is formed with a large size, it takes a rather long time for the ink which is usually of high viscosity to spread across the overall effective area of the perforated plate 4. And since the ink is charged into the ink holding chamber at only one area of the chamber or more particularly, through the center through hole 3 in the support frame 1 via the aligned holes in the bracket and frame, the stencil paper 10 receives more ink at its center area than the paper does at the rest of the paper resulting in uneven distribution of ink across the stencil paper and thus, a satisfactory printing result cannot be obtained.